From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 90489C77B75 for ; Fri, 19 May 2023 10:36:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=RdT4o3uhkgyuNMzPteOHlbj7qWmIXzBoCHzZ8jvzX9k=; b=N4kqNhBS3+Ioes suRAE6UmHXmIs+3IO8lxfiMKkiKbZonLJotqXGHNQMvJYzjdmp3I3hk7vpL3Z2gHCtroYnT13D5gO bCWqnmSwbZ1Y/EFHOu9YKB/nju/iG/Ee/lRm1gzIQrszERafhlsCpIG7D+PznYOlT2fig3ESpp4jN YQdi66txJ7coO8xn/15ihkZgEwmj2MyUbuyaeYa0YAzin/MiXbbkaXmLq7PlaTvJ52f9+Kl0CQEmq vt4/ZXzGnQJcApzA3rLCtQXBwtsqdBlXXPOa5+CyyRrapBG9OKY0zlCvrOgnIANTT+2hs3CK+OF2d IxRuon3+QKw3sS2L8a8A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pzxSu-00FuvA-1s; Fri, 19 May 2023 10:36:04 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pzxSq-00Fuua-2e for linux-arm-kernel@lists.infradead.org; Fri, 19 May 2023 10:36:02 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C2A7161454; Fri, 19 May 2023 10:35:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED94DC433EF; Fri, 19 May 2023 10:35:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684492559; bh=ouwTlWeIwuaIv/FUAfcm5AhKCglrsSeVlq0P9cdr61Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Z167pNooZBeA2Z9miu/zLx4z29vj2Dzi3yOWLjgzFzHdDkVcscNlNBmTiCJ3XWJ3O i6SIpzt6NQ3aZayc6a7VlF/2boCVbK4KgUb0RThY3Ucm9hu/7f9HMFtGyj7qCAg2tC GJHXDGGseeHYKvwex4zFk2/lKUTO/4suSXSLbA5ghVIk32ivPSBgXBYc+4YIq8gxxo 6GldZ4xpT5jIfnDMFQV+M79WV79xq/kb8Zm0IJB/ht/8NgTXIryB3Pbk5IR2sySGOs CuK9cI+Z99iYwnO4l6Mbh3mhWA4Pwc6yopkyYyT66yV7nlaiP9autvSHm5rYL5hdha fc++KBgK/Jg+A== Date: Fri, 19 May 2023 11:35:54 +0100 From: Will Deacon To: Catalin Marinas Cc: Marc Zyngier , linux-arm-kernel@lists.infradead.org, "Justin M . Forbes" , Mike Rapoport , Andrew Morton Subject: Re: [PATCH] arm64: Make the ARCH_FORCE_MAX_ORDER config input prompt unconditional Message-ID: <20230519103553.GA2287@willie-the-truck> References: <20230503123342.90538-1-catalin.marinas@arm.com> <86edndljkj.wl-maz@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230519_033600_957428_068DADF5 X-CRM114-Status: GOOD ( 28.19 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, May 18, 2023 at 05:04:26PM +0100, Catalin Marinas wrote: > On Thu, May 18, 2023 at 04:56:28PM +0100, Marc Zyngier wrote: > > On Wed, 03 May 2023 13:33:42 +0100, > > Catalin Marinas wrote: > > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > > > index b1201d25a8a4..1867aba83ba3 100644 > > > --- a/arch/arm64/Kconfig > > > +++ b/arch/arm64/Kconfig > > > @@ -1516,7 +1516,7 @@ config XEN > > > # 16K | 27 | 14 | 13 | 11 | > > > # 64K | 29 | 16 | 13 | 13 | > > > config ARCH_FORCE_MAX_ORDER > > > - int "Order of maximal physically contiguous allocations" if EXPERT && (ARM64_4K_PAGES || ARM64_16K_PAGES) > > > + int "Order of maximal physically contiguous allocations" > > > default "13" if ARM64_64K_PAGES > > > default "11" if ARM64_16K_PAGES > > > default "10" > > > > This patch (and the previous one) has the unfortunate side effect of > > completely breaking a change of page size (from 4k to 16k, for > > example): > > > > > > maz@valley-girl:~/hot-poop/arm-platforms$ make defconfig > > *** Default configuration is based on 'defconfig' > > # > > # configuration written to .config > > # > > maz@valley-girl:~/hot-poop/arm-platforms$ egrep 'PAGE_SHIFT|MAX_ORDER' .config > > CONFIG_ARM64_PAGE_SHIFT=12 > > CONFIG_ARCH_FORCE_MAX_ORDER=10 > > maz@valley-girl:~/hot-poop/arm-platforms$ make menuconfig > > configuration written to .config > > > > *** End of the configuration. > > *** Execute 'make' to start the build or try 'make help'. > > > > maz@valley-girl:~/hot-poop/arm-platforms$ egrep 'PAGE_SHIFT|MAX_ORDER' .config > > CONFIG_ARM64_PAGE_SHIFT=14 > > CONFIG_ARCH_FORCE_MAX_ORDER=10 > > > > > > The build then fails in ways that aren't obvious (BUILD_BUG in the THP > > code). It would much better if the result of the configuration tool > > would produce something that can actually build. > > Thanks Marc for reporting this. The main culprit is the removal of the > ranges, so MAX_ORDER stays at 10 when changing the page size, but only > with EXPERT enabled. With this patch, it just generalises the problem > even without EXPERT. > > So we either re-introduce the ranges or we drop the menuconfig entry > completely, regardless of EXPERT. I'm inclined to go with the latter, > just don't allow people to redefine this (still unclear to me if we need > a higher default with 4K pages). It doesn't solve the issue, but I'll drop this patch for now since it sounds like we're going to be reworking this further and we may as well avoid the churn. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel